Apparatus for classifying sheet material



cfL. TAYLOR July 28, 1942,

APPARATUS FOR CLA SSIFYING SHEET MATERIAL 6 Sheets-Sheet 1 7 Filed Jan. 21, 1959 'INVENTOR.

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APPARATUS FOR CLASSIFYING SHEET MATERIAL Filed Jan. 21, 19:59 a Sheets-Sheet 4' INVENTOR. CZA Pf/VCE 1. 7A YZOIE ATTORNEYS c. 1.. TAYLOR I APPARATUS FOR CLASSIFYING SHEET MATERIAL July 28, 1942.

- Filed Jan. 21, 1959 e Sheets-Sheet 5 f INVENTOR.

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APPARATUS FOR GLASSIFYING SHEET MATERIAL..

Filed Jan. 21, 1939 6 Sheets-Sheet 6 INVENTOR. C'Z/IIPE/VCL 1. 7A V20)? ATTORNEYS Patented July 28, 1942 UNITED STATES PATENT OFFICE armaa'rus roa zifi s smrmo sun s r Clarence L. Taylor, Youngstown, Ohio, assignor to The Aetna-Standard Engineering Company, Youngstown, hio,'a corporation of Ohio Application January 21, 1939, Serial .No. 252,152

7 Claims. (01.198-41) This invention relates to classifiers for gauging sheet materials and separating the gauged sheets in accordance with variations in their thickness. The invention is described herein in its application to the production of tin plate but it is to be understood that the invention may be used in conjunction with other materials and that the description of the preferred form of my invention contained herein is given only by way of example.

Users of. tin plate require that the thickness 'of the sheets furnished them be maintained within veryclose tolerances. Sheets that are too thick or too thin are likely to result in defective products or in the breaking of the dies "of the can making machinery. Therefore it is essential for manufacturers of tin plate accurately to classify the sheets in accordance with their thick-- ness to insure delivery of sheets of proper gauge to their customer. For the sake of economy it is essential that the classifier apparatus operate at high speed without damaging the sheets and that the classifier accurately pile or stack the sheets so that they can be handled conveniently.

Accordingly it is an object of my invention t0 v provide a classifier which will meet the above noted requirements. A further object is to pro-. vide a classifier which can be readily adjusted to handle different sizes of sheets and to operate at diiierent speeds. ,Another object is to provide a high speed apparatus for continuously shearmentary side elevation on an enlarged scale showing the entering end of the classifier; Figure is a plan view of the feed end of the classifier showing approximately the same portion of the machine that is illustrated in Figure 4; Figure 6 is a vertical section taken along line 6-6 of Figure 3; Figure 7 is a planvlew of the delivery end of the classifier; Figure 8 is an end elevation of the deliveryend Figure 9 is a detail of a portion of the belt supporting mechanism; and Figures 10, 11 and 12 are details illustrating the construction of the magnets employed in the classifier to prevent the sheets from flying through the air.

My apparatus is particularly adapted for use in conjunction with modern tin mills of the continuous type in which the metal is delivered after I illustrated a preferred layoutvof my apparatus.

ing sheet material such as tin plate into sheets of predetermined length, classifying the sheets and separately stacking the classified sheets. A

further object is to provide such an apparatus which is adapted to operate accurately at high speeds without damaging the material. Another object is to provide a classifier of simple and sturdy construction, and in which the parts are readily accessible for replacement and repair.

Various other objects of my invention will 'become apparent from the following description cf a preferred embodiment thereof, reference being made to the accompanying drawings. The essential characteristics are summarized in the claims:

In the drawings, Figures 1 and 1a diagrammatically illustrate a classifier made in accordance with my invention showing the arrange- -ment of the associated equipment; Figure 2 is a diagram showing a preferred wiring arrangement for the electrical controls for the classifier and associated equipment; Figure 3 is a side elevation fore being shipped to the customer.

the rolling operation in the form of bright annealed electrolytically cleaned coils of tin plate which require only to be sheared to the proper length and classified'according to thickness be- Ordinarily there are slight, but important, variations in the thickness of the rolled strip, and it is because of these variations that the sheets must be classified and sheets of ,the desired thickness separated from those sheets of greater or lesser thickness. In Figures 1 and lo I have diagrammatically for shearing and classifying strips of tin plate formed on a continuous mill. As shown in the drawings, a strip S of tin plate is fed from a coil C by a suitable uncoiling device through an edge trimmer indicated at 20. This is driven by an electric motor 2| wl'lich exerts sufiicient tension to unwind the strip from the coil. Beyond the of the classifier, some of the parts being omitted for convenience of illustration; Figure 4 is a fragedge trimmer the strip' is allowed to sag, as shown, to give a little slack in the strip to take 'care of fluctuations in thespeed of the following apparatus, and is then passed through felt pads indicated ,at 22 which function to remove dust and chips from the strip. Then the strip is automatically gauged by a continuous gauging device 23 preferably of .the type manufactured by the Pratt 8: Whitney Company and known as the Electro Limit.

From the gauge .23, the strip passes through a roller leveler indicated diagrammatically at 2|,

pinch rolls 25, and thence to the rotary shear 28. the roller leveler, pinch rolls and shear being driven by a single motor 21. Change speed gears (not shown) are incorporated in the drive of the shear 26 so that the shear can be adjusted to cut difierent lengths of sheets. The construction and arrangement of the gears, shear and associated no part of the present invention and accordingly will not be described further herein.

From the shear 26, the sheets are delivered to the classifier proper which is illustrated somewhat diagrammatically in Figure 1a. The details l of the. classifier will be described later, but for the present it will be suflicient to state that the sheets are deposited on-a conveyor belt 30 driven by a'motor 3|. The speed of the belt is greater than the peripheral speed of. the shear and the lineal speed of the strip entering the shear so that the sheared sheets will be longitudinally separated as they are deposited on the belt. For example, if the strip entering the shear is moving at a speed of say 600 it. per minute, the belt 30 may be operated at a speed of about.l,000 ft. per minute, it being desirable to space the ends of successive sheets a distance of. approximately 1 ft. Obviously thedifierence in speed between the belt 30 and the strip necessary to accomplish the desired spacing depends upon the length of sheets being cut by the shear.

1 After leaving the belt 30, the sheets if they are of proper gauge pass over the flipper or deflector 32 which is pivotally mounted on a shaft 33 and arranged to be raised or lowered. by a solenoid 34 controlled by the continuous gauge 23.

The gauge 23 and the control circuit for operating the solenoid 34 do not per se form a part of this invention, a suitable type of gauge being disclosed in United States Patent No. 2,007,840. For the purposes of this specification, it will suflice to say that a suitable type of gauge comprises two small rollers which are adapted to be in continuouscontactwith opposite sides of.the strip to 'begauged, which holds themapart its own thickness. Any variationin strip thickness will result in a variation in the distance between the two rollers. The relative movement of the two rollers controls the position of an armature disposed between two coils of an inductive bridge. Thus movement ofthe armature will change the characteristics of the bridge, thus changing the flow of current in the electrical circuits including the bridge. indicating instrument which shows variations in thickness of the strip from the predetermined standard, and the changes in electric current may also be employed to,control various instrumentalities such as the solenoid 34.

In the present instance the circuit is arranged the solenoid 34 is energized to raise the so that flipper 32 and thus deflect the sheets downwardly beneath the flipper in the event that the thickness of the strip material varie from a predetermined standard an amount in excess of the established tolerances. The necessary delay between the passage of the strip through the gauge and the operation of the solenoid and flipper is maintained by 'a tachometer generator whichsynchronizes the time delay between gauging the strip and sorting the sheets with the speed of the shear and strip; Thus if the strip becomes too thick in passing through the gauge, the solenoid will not be operated immediately but its operation will be delayed until a sheet cut from the thicker portion of the strip reaches the zone immediately ahead of the flipper 3 2.

, So long as sheets of'proper thickness are being delivered the solenoid will not be energized, the flipper will remain in substantially horizontal position and the sheet will pass over the flipper high speeds on the order of 1,000 a. er minute.

Necessarily the speed must be reduced gradually inorder to make is possible to accurately stack the heets without damaging their edges. Therefore the belt 35 is driven by the motor 36 at a reduced speed, say 320 ft. per minute, if the belt '30 has been operating at 1,000 ft. per minute.

From the belt 35 the sheets pass to belt3l where the speed is further reduced. Inthe examplegiven, this'belt may be driven at the speed of the shear, say 600 ft. per accomplished by the motor 38. Thuson belt 31, the sheets will be closely spaced.

From the belt 31, the sheets are discharged onto the final belt 39 disposed at a slightly lower level than belt 31 and driven at considerably slower speed. In the example given the speed of the belt 33 may be about 240 ft. per minute. Because of this very considerable reduction in speed,-it will be evident that the sheets will be discharged into belt .39 in overlapping relationship. That is to say, they will be shingled as diagrammatically indicated in Figure 1a of the drawings.

From the belt 39 the sheets are passed between roll 40and 4| and over roll 42, all of which are driven in synchronism with the belt by the motor 43, and discharged onto the elevating platform 44. The constructionand arrangement of the discharge mechanism and guides 45, 46 and 41 associated with the platform form an important part of my invention and will be described in detail below. The platform 44 is arranged to be raised or lowered by any suitable elevating mechanism indicated in general at 48, and in op-v eration the platform is gradually lowered as sheets are discharged thereon.

In the event that a sheet of incorrect thick-v ness is delivered onto belt-30, then by the control mechanism briefly described above the sole-- noid 34 will be energized to raisethe flipper 32 to the dotted line position of Figure la "of the drawings as the sheet approaches the solenoid. Thus the sheet will be deflected downwardly to the belt 35' disposed beneath belt 35. Sheets of incorrect gauge are then carried along belts 31' and 39' similar to belts 31 and 39 previously described; the belts being driven by motors 36', 38' and 43'. The discharge mechanism includes rollers 40', 4|, 42 and elevating platform 44' with associated guides 4 5', 46' and 41', the platform being raised and lowered by the elevating mechanism 43'.

Sheets of tin plate, being very thin and light,

are. extremely difiicult to handle at high speeds.

In previous types of machines difllculties frequently occurred not only because of the tendency of the-sheets to become diverted in their travel through the machines so that the edges of the sheets were not parallel with the line of travel, but also because at high speeds such as those at which my machine is adapted to operi ate the sheet have a tendency to sail through the air instead of remaining in position on the belts. The planing of the sheets in prior types Y of machines prevented their operation at speeds approaching the speed of operation of my machine as the flying sheets of tin plate were exand be delivered to the belt 35. The sheets upon tremelydangerous to the operators of the machines. To overcome this difliculty, I employ electro-magnets disposed beneath the conveyor belts and functioning to retain the sheets in position on the belts. The magnets are indicated at M in Figure 1a, and the construction and'- minute, the drive being varied in order to obtain proper operating conditions. So far as I am aware the best operating speeds for each particular size of sheet can only be determined experimentally. Therefore a control system by means of which various speeds can be obtained readily without stopping the machine is essential to efiicient' operation of the machine. To attain this end, I preferably provide individual motor drives for the belts, the shear and the edge trimmer as described above and provide each motor with an individual speed control so that its speed can be varied independently of the speed of every other motor. Further all of the motors may be stopped and started simultaneously and the speed of all of the motors may be varied simultaneously by means of Ward-Leonard control system.

The wiring arrangement for this control is shown diagrammatically in Figure 2 in which the Ward-Leonard, or variable voltage, generator is indicated at 50. The field current on the generators is controlled by the rheostat 5| which varies the output of the generator. The current generated is delivered through conductors 52 and 53 to armatures of the motors 2|, 21, 3|, 36, 36', 38, 38', 43 and 43' which are all connected in parallel with the result that if the rheostat is adjusted, for example, to increase thefield current of the generator the speed of all of the motors will be increased, and conversely if the generator field is weakened the speed of all of the motors will be reduced. Individual control to separately adjust the relative speeds of the motors is attained by the motor field rheostats R-M, Ra-Tl, and R-3l, R-36, Bit-36", R88.

cept for the supports furnished immediately adjacent the upright members 63,. and 88. Beneath the girder 86, longitudinally extending members 81 and 68 are provided which function to support the field rheostats. Rr3l, etc. for controlling the speeds of the individual motors, the backs of these rheostats being shown 'in Figure 3. By this construction, the driving mechanism and controls are all concentrated along one side of the machine,'making them readily accessible to the operators, while the opposite side of the machine is open except in the immediate vicinity of the vertical supports 63, 64 and 65. Thus the conveyorbelts are readily accessible and can be replaced easily without tearing down the machine and because of its open construction the operation of the machine can be clearly observed so that any necessary adjustments can be made.

As previously pointed out, the sheared sheets are discharged from the shear 28 onto the conveyor belts 30 which operate on, rollers or pulleys 69 and 690., the pulleys 69 being driven by a shaft 10 while the pulleys 690. are idlers. The shaft 10 is supported by bearings H and Ila mounted in bracket 16 at opposite sides of the machine, and at its end is provided with a sprocket 12 so that it may be driven by the motorv 3| through the chain 13.

In order to provide means whereby the level of the belts 30 may be adjusted to accommodate '1 the belts to variations in the level of the pass R-38', lit-43 and Rr-43', respectively, which are I carried by the frame of the classifier. Weakening the shunt fields of the motors by means of the rheostats increases their speed, and strengthening the fields reduces their speed. By this arrangement very flexible control is obtained. The speeds of all of the motors can be adjusted to best advantage by the-Various field rheostats and the entire machine can be stopped or started or varied in speed during operation by rheostat 5| without changing the individual setting of the field rheostats.

By this control scheme not only can the machine be operated to best advantage but also no time is wasted when the machine must be stopped, for instance to supply a new coil of material, as the entire apparatus can be stopped by the rheostat 5| and immediately started again with all of the various motors operating at correct relative speeds.

Referring to Figures 3 to 8, inclusive, it will-"be seen that the mechanism is supported on a suitable fioor or base by frame members 80, 8| and 82 and suitable vertical frame members 83, 8| and 65which are duplicated on opposite sides of the machine. The motors and associated driving mechanism are supported by a girder or beam 86 which extends longitudinally of the machine along one side thereof and which is supported by'the upright members 63, 84 and 65. It will be noted that the girder 66 is a box .construction and as shown particularly in Figure 6 supports ali'of the driving mechanism and the belts, ex-' line through the shear, the bearings for the pulleys 690. are supported by suitable brackets 14 on longitudinally extending rods 15, which are in turn mounted on the transversely extending bracket 16 supported by bearings 18 in the girder 66 (see Figures 4, 5 and 6). The end portion of the bracket 16 is concentric with the shaft Ill and the bearings ii are disposed within the end of the bracket 16. Thus the bracket and arms 15 may be rotated about the axis of shaft 10 to raise and lower the belts 30 without changing the distance between the pulleys 69a and thepulleys 69.

The belts 30 are supported at the desired level,

either at or slightly below the pass line of the shear, by rods 80 pivotally mounted at their lower ends to a suitable frame member or support M as at 82. At their upper ends, the rods are piv-' otally connected as at 83 to a transversely extending bar 84' extending within the belts 30 and channeled to receive the rods 15, the bar being cut away preferably as indicated at 81 in Figure 9 and being provided with suitable mechanism whereby the bar may be clamped to the rods 15, such as a cover plate 85 secured in clamping engagement with the rod 15 by screws 86. It will be evident that byloosening the screws 86, the bar 84 can be slid along'the bars 15 in either direction to raise or lower the pulleys 68 supporting the belts 30. Further adjustment of the level of the pulleys 69a and belts 30 can be made by means of turn buckles 88 which are preferably incorporated in the supporting rods 80. By this means the belts 30 can be adjusted vertically to a suflicient extent to insure that the sheets will be properly delivered by the shear. As noted above, the belts 30 are preferably driven at a higher speed than the peripheral speed of the shear so that the sheets are spaced apart as they are deposited thereon.

From the belt 30 the individual sheets pass either above or bl low the flipper or deflector l2,

depending upon whether the sheets are of standard thickness or not. The deflector 32 is mounted upon a. shaft 33 which is supported for rotation by suitable bearings in the girder 66 and -in the bracket 89, mounted upon the frame member 63. The deflector 32 is rotated from one position to another by the solenoid 34 through a connecting rod 99 and crank arm 9| keyed to the shaft 33, the solenoid being actuated in response to changes in strip thickness as described above. As long as strip of standard thickestablished tolerances the deflector 32 will be raised to the dotted line position shown in Figure 1a to deflect the sheets downwardly onto the lower series of belts.

Assuming that the sheets delivered to the belts '39 are within the established tolerances, then the sheets will be delivered over deflector 32 to the belts 35, a roller 9la being interposed between the deflector and the belts to reduce the friction on the sheets in traveling between the successive belts.

The belts 35 are carried by pulleys 93 and 93, the arrangement being generally similar to the supporting mechanism described in conjunction with the belts 39; i. e., thepulleys 93 are driven by a shaft 95 which extends through and is supported by abracket 96, similar to the bracket 16, and mounted in suitable bearings carried by the girder 66. The end of the shaft 95 is provided with a sprocket 91 so that the shaft may be driven through the chain 91a by motor 36. The idler pulleys 92 are supported by suitable bearings carried by brackets 98 mounted on rods 99 which are supported by the transversely extending bracket or arm 96.

To provide for vertical adjustment of the belts 35, a bracket I99 mounted on the girder '66 and supporting a bar I9I generallysimilar to bar 84, is. employed. The rods 99 andpulleys 92 may be raised and lowered by rotating the bracket I99 is driven by motor 39 throughchainl I93 and sprocket I99.

The belts 31 deliver the sheets to .belts 39 which are driven by motor 43 through mechanism similar to that previously described at'a velocity less than the velocity of belt 31 and less than the peripheral speed of the shear. The' belt is preferably disposedat a lower level tlian the belt 31, so that the sheets are deposited*"" thereon in overlapping or shingled relationship; as indicated in Figure la and carried thereby in this shingle arrangement to the piler mechanism at the delivery end'of the machine. The pulleys; for supporting the belts 39 and the associated brackets are similar in all material respects to the mechanism described previously with respect to belts 35 and 31 except that two brackets II9,'

similar to the brackets I99 and I91 previously described, are employed in conjunction with two bars III for supporting the longitudinally extending bars "-2 because the belts 39 are considerably longer than the belts 35 and 31, the additional length being necessary to convey the sheets beyond the piler mechanism for the offconcave and convex fabric rolls H5 and H6, theroll II5 being driven by a chain H1 and suitable sprockets at substantially the speed of the belt about its pivot and sliding the bar I9I along the rods. Only a small amount of adjustment is provided for the level of the belt 35 as no great range of adjustment is required.

The tension on the belts 35 can be adjusted by moving the brackets 93 along the rods 99 by means of nuts I92 in threaded engagement with the rods. A similar scheme is employed for adjustment of the tension on the belts 39.

As previously noted, only sheets of standard gauge are carried by belts 35, the velocity of the sheets as they are delivered to belts 35 is substantially the velocity of the belts 39, for example about 1,909 ft. per minute, and the slowing down of the sheets so that they can be stacked accurately and without damage is started on the belts 35. Thus the belts 35 may be operated at a speed of about 890 ft. per minute. From the,

belts 35 the sheets are delivered to belts 31 where the velocity is further reduced, preferably to such an extent that the sheets are deposited on the belt with very little space between the sheets.

The belts 31 are carried'by pulleys E93 and I93 and supported by a transversely extending bracket I95, rods I96 and adjusting bracket I91, all substantially identical with the mechanism described for supporting the belts 95. The driven pulleysiil i are keyed to shaft lBBa which 39. The rolls H5 and H6 are constructed of cotton or other suitable material much in the manner of buffing wheels and are given concave and convex contours so that the sheets passing between the rolls are bent in such a manner that their upper surfaces are concave, thus increasing the rigidity of the sheets and preventing their forwardends from bending downwardly until the rear portions of the sheets have been released from the rolls.

To provide adequate pressure between the rolls H5 and H6, the upper roll H6 is supported by bearings mounted on brackets I 29 carried by a rotatably mounted shaft I2I. The adjustable springs I22 and I23, mounted on the main frame and engaging above and below lever I24 rigidly.

connected to shaft I2I, maintain the roll H3 in engagement with roll 5 with the desired pressure.

The sheets as they are discharged immediately assume their previous flat condition and are projected forwardly and downwardly onto a suitable platform 44 which may be elevated by the elevating mechanism 43 to a position so that the top of the pile'of sheets is within the area enclosed by the side guides 41 and the members 99. The position of the elevator may be manually controlled by any ordinary means, the practice being to gradually lower the platform as sheets are deposited thereon.

' The stops or guides are carried by an arm E29 adjustably mounted on rods I29 and I39 supported by the main frame structure. The arm is formed.

To insure that each sheet will be projected with suflicient velocity from the pinch roll H5 and II to cause it to abut the end guide 45 and also 46 with the result that a straight pile of sheets to straighten out any sheets that may be slightly deflected in their travel through the machine, I preferably employ a roller I33 of polished steel driven by sprockets I34 and I35 and chain I36 at substantially the same velocity as the belt 39. The sheets dropping from the grip of the pinch rolls are given a slight forward impetus by the roller which is suflicient to straighten out the sheets and give them suflicient velocity to cause them to be piled in a straight pile with their forward edges abutting the stop 45.

As described in conjunction with Figures 1 and 1a, magnets are preferably employed to control the passage of the sheets through the machine and to hold the sheets down on the various conveyor belts. These magnets are disposed beneath the belts and are of generally two types. At the forward end of each belt, a, magnet is provided which is incorporated in the bracket sup:- porting the forward pulley. For example, the forward magnets for the belts 30 and 35 are set in recesses indicated at I40 in the brackets I4 and98, respectively. Throughout the machine magnets for the remaining belts are similarly disposed. v

Likewise magnets are provided adjacent the rear pulleys of each belt, the coils for these magnets being set in recesses I42 in the supporting brackets such as brackets 16 and 96.

The magnets intermediate the ends of the belts are preferably constructed so that they may be adjusted to the most desirable position as illustrated in Figures 10, 11 and 12. As shown, the magnets may comprise body portions I50 provided at their ends with grooves I5I adapted to receive the belt supporting bars such as the bars I6 for the belts 30 or the bars 99 which support the belts 35. The body portions are provided with oval recesses to receive the magnet coils I52, the recesses being closed by the cover plates I63. The magnets may be slid to any desired position along the belt supporting rods and may be retained in their adjusted position by set screws I54. Current may be supplied to all of the magnets by any convenient conductors (not shown). The magnets function to hold the sheets in en gagement with the various belts, thus preventing the sheets from planing and also assisting in preventing the sheets from being twisted or turned in their passage through the machine.

As previously described in connection with Figure 1a, the flipper 32 is raised by the solenoid 84 whenever a sheet of incorrect gauge is approaching the flipper so that any such sheets will be deflected downwardly un'der'the lower series of belts 36', 31' and 39' and finally discharged onto the elevating .platform 48'. The arrangement of the belts and their driving mechanism is in all material respects the same as the arrangementof the upper series of belt described in detail belts are marked with referencecharacters corresponding to those applied to the upper series.-

It is to be noted, however, that a series of conveyor rollers I60, I6I and I62 (see Figure 4) are mounted in suitable bearings on opposite sides of the frame structure and disposed generally beneath the deflector 32 so that the downwardly deflected sheets will be conveyed across the rollers and deposited on the first lower belt 35'. The forward magnet I63 beneath the belt 35' assists in holding the sheets in the proper course, and preferably one of the adjustable magnets is positioned as indicated at I64 beneath the belt 35' at about the point where the downwardly deflected sheets will strike the belt. By this arrangement, rapidly moving sheets can be deflected and properly deposited on the lower belt 35' without damage to the sheets and without danger of the sheets being displaced from their proper paths in passing through the machine.

By reason of its various novel features, my apparatus can accurately classify sheetmaterlal at very high speed. Because of my convenient control system, the various instrumentalities mak-- ing up my apparatus can be readily adjusted to operate at the most efficient speeds, and also all of the driving motors can be simultaneously started and stopped and their speed adjusted by adjusted readily to accommodate different sizes of sheets, and for all sizes within therange of adjustment the sheets are accurately and uniformly piled without damage thereto.

In the foregoing specification I have described in detail a preferred form of my invention. Various changes and modifications can be made therein without departing from the spirit and scope of my invention, and it is therefore to be understood that my patent is not limited to the preferred form described herein or in any manner other than by the scope of the appended claims.

Reference is hereby made to my divisional application, Serial No. 446,683 filed June 12, 1942, containing claims directed more particularly to the piling mechanism disclosed in this application; andto my divisional application, Serial No. 446,684, filed June 12, 1942, and containing claims directed more particularly to structural features of the apparatus disclosed in this application.

above, and the description will not be repeated carry sheets of ferrous material upon their upper here. Corresponding parts in the lower series of I claim:

1. In an apparatus for conveying thin sheets of ferrous material at high speed, a series of conveyor belts operating in the same direction, said belts operating at progressively slower speeds,

.and the receiving end of one of said belts being disposed below the discharge end of the imme diately preceding belt, and magnets disposed beneath the upper reaches of said belts adjacent the ends thereof for holding said sheets on the upper reaches of said belts at substantially the same speed as the belts and to prevent said sheets from planing through the air.

2. In an apparatus for conveying thin sheets of ferrous material at high speed, at least two generally horizontal conveyor belts adapted to v ew reaches, the receiving end of the second belt being disposed at a level below the level of the. discharge end of the first belt, means for driving said belts in the same direction, said first belt being driven at a higher speed than said second belt whereby the sheets are deposited on said second belt in overlapping relationship, and

means for causing sheets discharged from said first belt to be deposited accurately in the desired relationship on said second belt and for preventing such sheets from planing through the air comprising magnets disposedbeneath the upper reach of said first. belt adjacent the dis- 4 charge end thereof and beneath the upper reach of said second belt adjacent the receiving end thereof.

3. In an apparatus for conveying thin sheets of ferrous material at high speed, at least two generally horizontal conveyor belts adapted to carry sheets of ferrous material upon their upper reaches, the receiving end of the second belt being disposed at a level below the level of the discharge end'of the first belt, means for driving said belts in the same direction, said first belt being driven at a higher speed than said sec- 1 0nd belt whereby the sheets are deposited on said second belt in overlapping relationship, and

means for causing sheets discharged from said first belt to be deposited accurately in the desired relationship on said second belt and for preventing such sheets from planing through th'e air comprising a magnet disposed. beneath the upper reach of said second belt adjacent the receiving end thereof.

4. In an apparatus of the type described, the combination of two belts adapted to convey thin ferrous sheets at high speed, means for-driving said belts in the same direction, the first belt being adapted todeliver sheets to the second belt, and the second belt being driven at a slower speed than the first belt, and means for causing sheets to travel in the desired position on said belts and to prevent the sheets from'planing through the air at high operating speeds comprising magnets disposed beneath the upper reach of the first belt adjacent the discharge 7 end thereof and beneath the upper reachof the second belt adjacent the receivingend thereof.

5. In 'an apparatus for conveying thin sheets of ferrous material at high speeds having a first belt conveyor, a deflector, and an upper belt conveyor and a lower belt conveyor both operating in the same general direction as said first belt conveyor, said deflector being disposed between said first belt conveyor and said upper and lower ldelt conveyors and guiding sheetsdelivered thereto to either said upper belt conveyor or said lower belt conveyor; the combination of means for driving said conveyors at high rates of speed. and means for preventing sheets from planing through the air at high operating speeds and for insuring accurate positioning of the sheets on said upper and lower conveyors comprising a magnet disposed beneath the upper reach of said first belt conveyor adjacent the delivery end thereof, a magnet disposed beneath the upper reach of said upper belt conveyor adjacent the receiving end thereof, and a magnet disposed beneath the upper reach of said lower belt conveyor at the zone where said conveyor receives sheets from said deflector.

6. In an apparatus for conveying thin sheets of and means for preventing the sheets from plan ing through the air at high operating speeds and for insuring accurate positioning of the sheets on said second conveyor comprising a. magnet disposed beneath the upper reach'of said first belt conveyor adjacent the delivery end thereof, and a magnet disposed beneath the upper reach of said second belt conveyor at the zone where said conveyor receives sheets from said deflector.

7. In an apparatus for conveying thin sheets of ferrous material at high s eeds having a first belt conveyor, a deflector, and an upper belt con- .veyor and a. lower belt conveyor both operating in the same general direction as said first belt conveyor, said deflector being disposed between said first belt conveyor and said upper and lower belt conveyors and guiding sheets delivered thereto to either said upper belt conveyor or said lower belt conveyor; the combination of means for driving said conveyors at high rates of speed and means for preventing sheets from planing through the air at high operating speeds and for insuring accurate positioning of the sheets on said upper and lower conveyors comprising a magnet disposed beneath the upper reach of said upper belt conveyor adjacent the receiving end thereof, and a magnet disposed beneath the upper reach of said lower belt conveyor at the zone where said conveyor receives sheets from said defiector.

CLARENCE L. TAYLOR. 

